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Патент USA US2126885

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‘Aug. 16, 19.38.
' 2,126,835 '
ogiginal Filed Feb. 25., 1936
Patented Aug. 16, 1938,
' 2,126,885
Ralph M. Heintz, San Francisco, Calif" assignor,
by mesne assignments, to Bendix Aviation
Corporation, South Bend, Ind., a corporation
of Delaware
Application February 25,, 1936, Serial No. 65,638
Renewed June 16, 1938
2 Claims.
My'invention relates to‘ valve gear, and more
particularly to a system wherein valves are op
erated hydraulically.
Among the objects of my invention are: To
5 provide a valve gear wherein poppet valves may
be operated at an angle to an enginecylinder;
(01. 123-90)‘
valves in a radial engine having an L-head, at
an angle, particularly where the cylinders are
not all in the same plane, the valve gear be
comes intricate, and it has heretofore been
to provide a hydraulically operated poppet valve;
customary in such' radial engines to utilize,
primarily for the reason given immediately above,
overhead valves, thus losing the advantages of
to provide a means and method of eliminating air
in a hydraulic valve-lifting system; to provide a
means and method of lubricating a valve stem;
to provide ‘a means and method of preventing
an L-head. Tilted'valves, however, in an L-head
radial engine have‘ de?nite advantages if the
engine is to be air-cooled, inasmuch as by tilting 10
the valve, stem and guide can be separated from
oilfouling of a valve stem and guide, to provide
valve gear of relatively small inertia; and to
the engine cylinder and cooling applied to both
_ provide a simple and effective valve-lifting sys~
sides thereof.
I have therefore invented a hydraulic system '
which will allow valves in an internal combustion 15
My invention possesses numerous other objects
engine or other device to be set at different levels
and features of advantage, some of which, to
or even at different angles on the same engine
gether with‘ the foregoing, will be set forth in
and yet have the tappets all positioned in the
the following description of speci?c apparatus
same plane; and my invention also broadly com
embodying and utilizing my novel method. It
is therefore to be understood that my method is
applicable to other apparatus, and that I do not
column at a constant pressure-and a means and
method for eliminating or preventing air bubbles
prises means for maintaining the oil transmission 20
limit myself, if any way, to the apparatus of the
present application, as I may adopt various other
from entering this column. Furthermore, I may
desire to continually bleed the oil column and to
to Cl apparatus embodiments, utilizing the method,
use the oil thus obtained to lubricate valve stems. 25
within the scope of the appended claims.
I also prefer to provide a chamber back of the
Referring to the drawing:
valve stem and guide so that pressures may be
The ?gure is a view partly in section and. equalized on both ends of the valve stem, thus
partly in elevation of a preferred valve-lifting avoiding oil pumping around the inlet valve stem
system, built in accordance with my invention. and a complete drying up and carbonization of 30
Certain parts have been simpli?ed for ease of oil around the exhaust valve stem.
Other broad aspects of my. invention may be
Recently it has become relatively common in more fully understood by direct reference to- the
the art to utilize hydraulic valve clearance take
drawing. A poppet valve assembly is provided
ups, but these arrangements do not, in any way, with a valve head I supported on a stem 2. This
eliminate many‘ bad features of the purely valve is the conventional type of valve commonly
mechanical valve operating means, especially used in internal combustion engines, and is sup
when thevalves are applied to internal combus— ported by a combined unitary seat 3 and; guide 4.
tion engines. In this respect I wish to point 'out as described in my application, Serial No. 65,472
40 that my invention herein to be described, while ?led February 24, 1936 contemporaneously with
described as primarily adaptable for use in con
the present application, entitled Valve seat and
junction with an internal combustion engine,
can be used inlother devices, such as air com
guide. '
pressors for example; and furthermore, the valve
itself, while shown to be a poppet valve,-may,
bedded in the cylinder block 5 in such a manner
that it is at an angle to a cylinder, not shown,
» within the knowledge of those skilled in the art,
be of other types.‘ I do not wish, therefore, to
be limited to an internal combustion engine valve
gear, as the- advantages of my invention are
0 equally applicable to other devices.
In the ordinary valve setup wherein the valve
The valve seat and guide is preferably im
this angle, however, being such that air-cooling
fins 8-6 may be provided completely surround
ing the valve guide 4. The stem 2 of the valve
extends through the guide into a spring cham
ber ‘l containing'a ‘valve spring 9 compressed to "
exert pressure to close the valve through the me
is mechanically lifted through the agency of a dium of spring retainer III. The chamber com~
pletely surrounds the spring and is provided at
tappet and push rod, certain limitations are in
herent, particularly when applied to a radial ' the bottom with a lifter bearing ll, preferably of
55 engine. For example, if it is desired to place the hardened material, in which a lifter I2 slides, and 55
the lifter i2 is preferably provided with a bleeder
of oil is bled out into the valve chamber ‘I, and
hole I 4 through the center, the use of which w?l ' this oil, together with the relatively small amount
be described later.
leaking past the lifter bearing, ,serves to lubricate
the spring and stem. In like manner oil in small
From the back of the lifter i2 extends an
oil channel IS in which oil oscillates, being en
ergized by a tappet, [6 operating in a hardened
bearing ll, this tappet being driven by a; cam
tappet against the‘ cam l9. Such lost oil is au
is mounted on a-cam shaft 20, which is driven
‘in any convenient manner, as is well known in
tomatically replenished, as needed, through the
check valve 3|, thus insuring that the oil chan
10 theart, from the crank shaft of the engine to
which the cylinders and valves are attached. . In
case access is desired to the valve chamber, I
have split the cylinder casting in such a manner
that the split passes through the chamber, and
15 have inserted therebetween a gasket 2i to seal
the chamber, the two portions being held to
gether by bolts or clamps, as is well known in the
amount, leaking past the tappet bearing, serves
to lubricate the tappet and the bearing of the
nel i5 is at all times full, this feature at all times
eliminating any tappet clearance.
There are other features, however, inherent‘in ‘
the structure I have just described. For exam
ple, a mushroom tappet may be used to its maxi
mum extent because the tappet is perfectly free
to revolve without having to push up the valve
mechanically at the same time wearing the lifter
and valve stem in the meanwhile.
In addition, ,
One of the important features of my inven advantage may be taken of-a difference in lift
tion lies in the means and method by which I between the tappet and lifter by making the re-'
supply oil to the oil column which is contained spective diameters of di?erent size. In the pres 20
within oil channel i5. Inasmuch as the system ent preferred example the tappet moves about
herein described is adapted for use with a four
one-half as far as the lifter. Furthermore, the .
cylinder radial engine operating with the cylin
combined mass of the tappet, lifter and oil col
ders in the horizontal plane, I prefer to connect ‘ umn is but a fraction of that of any mechanical
the mainoil supply to a circular conduit 22, also system. Not only is valve stem‘ clearance entirely
in a horizontal plane. Theconduit 22, after al
eliminated, thus reducing the wear on the stem
most completing a circle, ends in a pressure re
tip and tappet, but- the valve itself is» lifted
' lief valve assembly 23 which, as7 is well known straight up, removing all side strain from stem
in the art, comprises a piston 24 positioned to and valve. Furthermore, as the slack in the tap
be pushed against a spring 25, thus uncovering pet is always being taken up, a new valve, even 30
more or less of apertures 26 in accordance with though the stem _be as much as V8 of an inch
the pressure. The pressure can be regulated by‘ too long or too short, can he slipped into" place
means of a spring-tension nut 21 so that when 'with no adjustment whatsoever; and as an incl
agiven pressure is reached within conduit 22, oil dental feature, austenitic steels __can be used for
is released through apertures. 28 to reduce the
the valve stems with great advantage, although
pressure. ' I also prefer to utilize the released oil
such steels can not be used satisfactorily with
mechanical systems because of a very large co
e?icient of expansion.
There is one more advantage, however, which
to lubricate other portions of the engine.
Vertical risers 29 are dropped from the oil con
40 duit 22, whichconnect with a ?lter chamber 30
through which oil is released into the oil chan
nel l5 through a check-valve assembly 3!, ?rst,
however, having passed through a ?lter screen 32.
I should be pointed out in the present device,‘ 40
namely, that the spring chamber 1 can be sealed
by the lifter l2. Heretofore engine ‘designers I
I prefer to make- this ?lter screen either of ‘have been content to run exhaust valve stems
multiple layers of mesh material or of single without lubrication, and to permit the exhaust.
mesh of such a size that an air globule, to pass . gases escaping past the valve stem to‘ enter the 45
through, must be smaller than .0001" in diame-_ crank case. Furthermore, mechanical systems
ter. Even with low viscosity oil at runningtem
allow the intake suction, to draw as much oil
. perature, the surface tension is so high that an
oil line pressure of thirty pounds per square inch,
for example, cannot force these small globules
through the filter. When enough globules have
‘Joined to- make one large enough to break the cm
hesion with the surface of the ?lter, the air bub
ble will rise in the vertical pipe 29 and be washed
outwith. the main oil stream‘ in oileonduit 22,
thus preventing air from entering the oil chan
nel it during operation.
Inasmuch asAthe important thing to consider
60 in a hydraulic drive of this sort is the elimina
from the crank case as, can pass the stems.
is very di?icult, with mechanical lifters, to ?t
pressure-equalizing chambers around the stem
guides and springs, but in my present invention
this is a simple matter- The lifter pistons form
the pressure seal, allowing the pressure in the
spring chamber to equalize itself with that in 55
the ports. With an exhaust valve the pressure
will be low, depending on the back pressure of the
exhaust pipes and mu?ler system. With the in
take valve, however, the conditions are quite dif
ferent, the pressure ranging from around. 20
tion of trapped air, the bleeding of freed air and inches
of mercury suction, with the engine idling
the ?ushing of the lines, the entire system has
been designed toward eliminating air. 'It- has al - _at sea level; to around 20 inches of mercury pres
sure when supercharging at high altitude is used.
ready been describedfhow air is prevented from With
my present system, however, I control the
' entering the oil ‘channel I5, but if by any chance lubrication of both the intake and exhaust stem,
air should ‘be left in this channel after servicing, ' and insure against inward leakage of air'or out
for example, it will work out, through bleeder
_ vhole II in the lifter l2.
wardly of mixture, throughout the wide range of
intake pressures at the intake valve.
This bleeder hole, however, serves another pur
‘While I have described‘m'y device as being
pose as well. ;Whi1e I have shown this litter, applied to a horizontal radial engine, it is obvious
in the‘ drawing, to be removed slightly from the that the same structure can be_applied,‘as de-.: 70
tip of the stem, normally hole I‘ _is completely- - scribed, to engines in any position, the main
sealed by thestem tip except when the pressure desideratum being only that’there be a means for
is relieved for a fraction of a second after the
valve" seats. ' At this moment a minute quantity
directing air‘bubbles from the?lter-screen into
the main oil stream to be thereafter swept out of
the system. It is possible then to eliminate the
vertical pipes entirely and pass the main oil
stream directly over the screens in such a manner
that the oil bubbles are swept away from the
vicinity of the screen before becoming large
enough to block the screen.
-I have also found that at least a pair of ?lter
chambers 30 can be supplied by one vertical con
duit 29, and I prefer to supply both valves of a
single cylinder with a single vertical conduit, thus
reducing'oil piping to a minimum.
I claim:
1. In combination, a poppet valve having a.
stem, a closed chamber around the inner portion
15 of said stem, a valve spring positioned within
said chamber and connected to said valve stem
for actuation of said valve, a valve lifter extend
ing through the wall of said chamber contacting
the end of said stem for actuation of said valve
20 against spring action, said lifter entering said
chamber through an oil-sealed bearing, and
means for intermittently lubricating said lifter,
stem, and spring through said lifter.
2. In combination, a poppet valve having a.
stem, a closed chamber around the inner portion
of said stem; a valve spring positioned within
said chamber and connected to said valve stem for
actuation of said valve, a valve lifter extending
through a wall of said chamber contacting the
end of said stem for actuation of said valve against
spring action, said lifter entering said chamber
through an oil-sealed bearing, and means for sup
plying oil to said chamber through a-conduit in
said lifter, opening between the contact faces of
said stem end and said lifter, said chamber being
gas-tight except for 'leakage‘around said valve 15
stem whereby entrance of oil to said chamber is
controlled by leakage pressure, and passage of oil
from said chamber lubricates said valve stem.
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